Max Loss is the realized losses on a trade. A realized loss is the losses on the closed trades by a client.
Total Loss is the realized and unrealized losses on a trade. An unrealized loss is the loss on an open trade by the client.
If you set a $500 Max loss, and you have a realized loss of $490, you can go into another trade. Your new open trade can lose $10, $100 or $500 but the Max loss will only restrict you from trading once you close that trade and realize your loss over $500.
A Total loss set at $500 restricts you from trading as well as liquidates your position once $500 in both unrealized and realized losses is reached cumulatively. In a scenario, if a $500 total loss is set and you have a realized loss of $490, you can get into a trade and once you go into a -$10 loss, your position will be liquidated and you will be prevented from trading.